Newcastle have confirmed that Jonny Wilkinson has undergone a second operation on his knee in the battle to overcome his latest injury.

Rumours surfaced over the weekend that the World Cup-winning fly-half faced further knee surgery after suffering a dislocation during Newcastle's Guinness Premiership game against Gloucester in September.

But the Falcons rugby director, Steve Bates, has revealed that the scheduled procedure has already taken place. "As was always the plan, the back-up to the original operation was to have an arthroscopy, which took place in the north-east a couple of weeks ago," Bates said. "That was to assess whether the initial operation had been a success.

"The surgeon who did that original operation is saying that everything looks OK to proceed on to the next stage of his rehabilitation, which will involve making sure that strengthening, flexibility and all those sorts of issues are dealt with. That has a timescale all of its own, depending on how he responds, but at least the initial hurdle seems to have been overcome."

Bates added: "There was always going to be a little doubt about whether the original operation had been a success, as with all operations. Now that we are hopefully past that stage, it's just a case of continually monitoring how he progresses, rather than now giving a timescale of when he will be back playing."

Wilkinson, who has seen Danny Cipriani and Toby Flood take over his England No10 shirt since the spring, is battling to be fit for the 2009 Six Nations Championship. England begin their campaign against Italy at Twickenham on 7 February, when the 29-year-old Wilkinson is likely still to be sidelined.